/Engine/Plugins/Animation/IKRig/Source/IKRig/Public/Rig/IKRigSkeleton.h
Given a set of bones, returns a set of indices of bones that are mirrored across X axis (YZ plane) return false if any of the bones do not have a mirrored pair within the MaxDistanceThreshold
bool GetMirroredBoneIndices ( const [TArray](API\Runtime\Core\Containers\TArray)< int32 > & BoneIndices, [TArray](API\Runtime\Core\Containers\TArray)< int32 > & OutMirroredIndices ) const